A known seat slide apparatus for a vehicle may include a memory function. According to the known memory function, in a case where an upper rail moves in a front direction of a seat relative to a lower rail when a seatback is in a forward-folded state, the memory function memorizes a relative position of the lower rail and the upper rail relative to each other before the movement of the upper rail (which will be referred to also as “a memory position”). For example, a known seat slide apparatus for a vehicle described in JP2006-281814A (hereinafter referred to as Patent reference 1) includes a component for position memory which is provided at a bottom wall portion of a lower rail opening upwardly and including a substantially U-shaped cross section. The component for position memory is arranged to extend in a long-side direction of the lower rail. In addition, the known seat slide apparatus includes a memory base which is movably provided at the component for position memory, and is engageable with and disengageable from the upper rail. The known seat slide apparatus includes a memory plate which is supported at the memory base and is engageable with and disengageable from the component for position memory. An engagement state between the upper rail and the memory base, and an engagement state between the component for position memory and the memory plate have a contradictory relationship to each other.
For example, in a case where the lower rail and the upper rail are moved relative to each other in a normal operation state, the memory base and the memory plate are configured to move integrally with the upper rail in a long-side direction of the component for position memory.
On the other hand, in a case where the upper rail moves in the front direction of the seat relative to the lower rail when the seatback is in the forward-folded state, it is configured that the memory plate is engaged with the component for position memory, and the memory plate and the memory base remain at a present position. Thereafter, in a case where the upper rail moves in a rear direction of the seat relative to the lower rail, as the relative position of the lower rail and the upper rail returns to the memory position, it is configured that the upper rail comes in contact with the memory base. Accordingly, a further movement of the upper rail is restricted.
According to Patent reference 1, the component for position memory and the like are provided at the bottom wall portion of the lower rail to achieve the above-described memory function. However, depending on a specification of the lower rail and/or a fixation structure of the lower rail, a space for arranging the component for position memory and the like may not be ensured at the bottom wall portion of the lower rail, and therefore the memory function may not be achieved.
A need thus exists for a seat slide apparatus for a vehicle which is not susceptible to the drawback mentioned above.